Systems Philosophy, Systems Engineering Philosophy,
Systems Approach Systems Science, Systems Thinking, Systems Models;
Systems Design; RSM, TRIAD Systems Methodology
Land Force 2010;
Systems Engineering
Systems Architectonics Complexity,
The Hitchins 5-Layer SE Model

Basic Models for System Thinking

Prof. Derek Hitchins

Contents

Fundamentals

The concept "System" is one of organization, structure, relationship, order, method

Systems may be:-

One system may exhibit more or less order than another:-

First System Model

This a nesting model, of systems within systems within systems...

Poached egg

This simple model provides surprising strength and clarity of perception once applied to real situations, to identify real system relationships. for instance:-

These ideas of containment and hierarchy couple with the concept of emergence. The Containing System above contains several interconnected siblings, including the SOI. Because the SOI and its siblings mutually interact, their combined effect is not the same as though they were virtually separate, like snooker balls in a bag.

Instead, the Containing system will exhibit some properties, capabilities and behaviours which emerge from these interactions. As a result, even simple systems, with few siblings, may exhibit quite unexpected behaviour, varying from oscillations to deterministic chaos.

Don't let the simplicity of the model blind you to the potential complexity of the behaviour. That would be to think in static terms. System thinking is dynamics.

System Definition and Ideas

System:-

"An open set of complementary, interacting parts with:-
emerging both from

The definition presents ideas of:-

Babushka Dolls

Babushka Russian Dolls - Russian-style

The First System Principle and Corollary

human frame

First Principal of Systems:-

The properties, capabilities and behaviour of a system derive from its parts, from interactions between those parts, and from interactions with other systems.

Corollary to the First Principle

Altering the properties, capabilities or behaviour of any of the parts, or any of their interactions, affects other parts, the whole system, and interacting systems.

Nature of System Models

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Second System Model

The model shows the same general idea as the first model above, but now the emphasis is on the openness of the system to inflows and outflows. As you can see, inflow might comprise energy, resources and / or information. Outflow might comprise residue, waste and / or product according to your viewpoint about any particular system. and the system itself has properties, shown in the box.

Open system

As for the first model, the second model is to be viewed dynamically.

Self-similarity, Nesting, Recursion and Hiding

Another way to look at nesting systems is shown below. Three open systems are shown interconnected. Reading the interconnection legends, you will see that:-

The interactions create complementary network. If all three systems are now "hidden" within the System container, you can see that the inflows and outflows from the container are also Energy/Dissipation, Resources/Residues and Information.

This is self-similarity up and down the hierarchy of containment.

Recursion

The combination of systems and interconnections may such that each systems requisite inflows are provided by other systems outflows, and vice versa. This situation creates a Complementary Set of systems. These are common in Nature and appear as ecologies. Economies can operate similarly, both at micro and macro levels.

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Generic Reference Model (GRM)

Systems methods are very powerful, and can address the solving of complex problems in a way unparalleled by reductionsit methods. However, systems methods - which are at the heart of systems thinking, systems, design, systems engineering and the systems methodology - are often misunderstood, since they often rely on representations of systems in the abstract: which can create some confusion amongst hard-nosed, pragmatic engineers, for example! The idea is explained in the Systems Methods, Systems Metaphors, System Abstractions which it may prove advantageous to read before "diving into" the GRM...

The GRM presents an "internal" view of any system. As the touch-active map below shows, it is possible to think of any system under three headings:-

  1. Being, the state of existence
  2. Doing, the state of activity
  3. Thinking, the state of sentience

Many system simply exist, without directed activity or sentience. e.g. the solar system. Some systems are able to do things, exhibit purpose and pursue goals, e.g. animals, assembly plants. Yet again, some systems can think, and can adapt their behaviour according to circumstance, e.g. higher animals, companies.

The GRM is developed using several formal approaches, to provide some rigour. As with all good system models, it is type independent and scale independent. It is expanded out in successive levels of decomposition, starting at the top level, the GRM Map

Generic Reference Model

Generic Reference (Function) Model

This model describes the "doing" features of any system that has such features. It comprises three parts:-

Together, these three form the "Management Set", so called, because they describe the management of their respective features.

Mission Management

All that any system can do in terms of pursuing a Mission is to collect information, set or reset objectives using that information (in part) strategize and plan the pursuit of Mission, Execute the plan and, if necessary, cooperate with others in the environment.

Closure of the circle corresponds with closure, i.e. completeness of the set of the set of continual actions.

Mission Management

 

Resource Management

Similarly, all that any system can do in managing resources is: acquire them, store them, distribute them, convert and utilize them, and discard any waste or product.

Closure of the circle corresponds with closure, i.e. completeness of the set of the set of continual actions.

Resource Management

Viability Management

Viability is altogether more complex:-

From the above, the following generic features have been carefully extracted to identify the basis of system viability.

Viability Management

Note the mutual interdependence of each feature:-

Mission Elements Together

The three figures above may be combined as shown, to show their mutual dependence:-

Function Model

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Generic Reference (Form) Model

Form is shown as comprised of three parts:-

GRM Form Model

In applying the model to a real-world system, one would have to identify these various influences, of course. Not always easy, but knowing that they must exist is a good start point.

Generic Reference (Behaviour) Model

Behaviour Model proposes how Behaviour might be selected generically:-

Of three first-level Models, Behaviour most complex, subtle.

GRM Behaviour Model

GRM as an Integrated Whole

GRM in Action

Instead, the GRM can be used in a powerful methodolgy for understanding emergence and for measuring effectiveness. Consider the following sequence of figures: -

Open system Interaction

The first figure shows two systems, Blue and Red, interacting in an operating environment. Only in such a dynamic, interactive situation is it possible to sensibly observe, say, Blue's emergent properties, capabilities and behaviours (PCBs). As Blue acts on Red through the environment, Red is affected and changes. This change is a measure of Blue effectiveness. But, Red also acts on Blue, so Blue is changed. Thus, once Red and Blue start to interact, each changes and is changed by, the other. This results in a dynamic, in which the emergent PCBs and effectiveness of both Blue and Red unfold over time. Thus, effectiveness is not some fixed, arbitrary figure, and is not really capable of being specified a priori. Instead it is an emergent property of the interaction of a system of interest (e.g. Blue) when it interacts with other systems in some operating environment.

This is not really news. The top speed of a sports car is only some 35 miles per hour when going through the centre of London, say. It may have potential for 135 mph, but that is not what it can achieve when interacting with other vehicles in a transport environment. News or not, people still insist on trying to specify effectivness as an independent variable, without regard to other systems or the environment. Wrong.

Open System Level 1

The second repeats the top level model of the GRM

Interacting GRMs 1

The third figure shows a Blue GRM interacting with a Red GRM in some Green environemnt

Interacting GRMs 2

The fourth figure in the series shows how an engaged system such as blue may be related to its logistics, procurement and supplier systems, in this case for a defence system such as a ship, a plane or a tank. Red might have a similar support.

In this way, as shown by the figures, it is possible to employ the GRM as a reference model in active situations. Such situations might include co-operation between two or more systems, competition between systems in some market, or conflict between two opposing groups. The model is still generic.

Finally in this set, the following diagram elaborates the previous Blue GRM to show the level of detail to which you can go - and still remain genericLayered GRMThe Function Model has been divided into its three constituents. Resource Management and Viability Management have been set to apply to all three layers, and Mission Management. This, then, could be used as a C3I model - see Command and Control on this web site - where C3I is Command, Control, Communications and Intelligence.

This layered model is only half of the model represented in the previous figures, where two interacting systems were seen to be necessary. A useful way forward, then, is to instatiate and replicate the layered model and connect up the two representations so that they may co-operate, compete, or engage eath other as appropriate. Instantiations of logistics supply can be added and connected up, as shown in the previous figure. One GRM can be held constant while the other is evolved using genetic or hill climbing algorithms, to achieve maximum effectiveness. The evolved GRM can then be held constant while the first is now evolved. And so on. I call this systolic evolution.

The method and approach are universal, as befits a system generic refence model and, here, a system generic reference method.

 

 

Well, there we are - that's a beginning. System models are many and various. Bak and Chen produced a useful model of sand trickling on to a pile, reaching a particular cone size, and thereafter maintaining that size as more sand was poured on, resulting in avalanches. They called this phenomenon Self-Organized Criticality. They were investigating tectonic plate movement, but the same phenomenon appears to apply to:-

So, systems models are many and various - and they can address so many complex things, in ways that conventional approaches simply cannot touch.

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Derek Hitchins

Last updated: Mar 2005

http://www.hitchins.net